<!DOCTYPE html>
<html lang="zh-CN">
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <meta name="robots" content="noodp" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge, chrome=1">
        <title>《Flutter Engine源码调试》 - 飞雪无情的博客</title><meta name="Description" content="专注于IT互联网，包括但不限于Go语言(golang)、Java、Android、Python、项目管理、抖音分析、软件架构等"><meta property="og:title" content="《Flutter Engine源码调试》" />
<meta property="og:description" content="
本文主要介绍Flutter Engine
" />
<meta property="og:type" content="article" />
<meta property="og:url" content="https://www.flysnow.org/posts/flutter/Flutter-Engine%E6%BA%90%E7%A0%81%E8%B0%83%E8%AF%95/" />
<meta property="article:published_time" content="2021-07-31T21:34:42+08:00" />
<meta property="article:modified_time" content="2021-07-31T21:34:42+08:00" />
<meta name="twitter:card" content="summary"/>
<meta name="twitter:title" content="《Flutter Engine源码调试》"/>
<meta name="twitter:description" content="
本文主要介绍Flutter Engine
"/>
<meta name="application-name" content="飞雪无情的博客">
<meta name="apple-mobile-web-app-title" content="飞雪无情的博客"><link rel="shortcut icon" type="image/x-icon" href="/favicon.ico" />
        <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png">
        <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png"><link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png"><link rel="manifest" href="/site.webmanifest"><link rel="canonical" href="https://www.flysnow.org/posts/flutter/Flutter-Engine%E6%BA%90%E7%A0%81%E8%B0%83%E8%AF%95/" /><link rel="prev" href="https://www.flysnow.org/posts/flutter/FutureBuilder%E4%B8%8EStreamBuilder/" /><link rel="next" href="https://www.flysnow.org/posts/flutter/Flutter%E6%B5%8B%E8%AF%95%E8%84%9A%E6%9C%AC%E5%BC%80%E5%8F%91/" /><link rel="stylesheet" href="/lib/normalize/normalize.min.css"><link rel="stylesheet" href="/css/style.min.css"><link rel="stylesheet" href="/lib/fontawesome-free/all.min.css"><link rel="stylesheet" href="/lib/animate/animate.min.css"><script type="application/ld+json">
    {
        "@context": "http://schema.org",
        "@type": "BlogPosting",
        "headline": "《Flutter Engine源码调试》",
        "inLanguage": "zh-CN",
        "mainEntityOfPage": {
            "@type": "WebPage",
            "@id": "https:\/\/www.flysnow.org\/posts\/flutter\/Flutter-Engine%E6%BA%90%E7%A0%81%E8%B0%83%E8%AF%95\/"
        },"genre": "posts","keywords": "flutter","wordcount":  2589 ,
        "url": "https:\/\/www.flysnow.org\/posts\/flutter\/Flutter-Engine%E6%BA%90%E7%A0%81%E8%B0%83%E8%AF%95\/","datePublished": "2021-07-31T21:34:42+08:00","dateModified": "2021-07-31T21:34:42+08:00","publisher": {
            "@type": "Organization",
            "name": "飞雪无情"},"author": {
                "@type": "Person",
                "name": "飞雪无情"
            },"description": ""
    }
    </script></head>
    <body header-desktop="" header-mobile=""><script type="text/javascript">(window.localStorage && localStorage.getItem('theme') ? localStorage.getItem('theme') === 'dark' : ('' === 'auto' ? window.matchMedia('(prefers-color-scheme: dark)').matches : '' === 'dark')) && document.body.setAttribute('theme', 'dark');</script>

        <div id="mask"></div><div class="wrapper"><div class="logo-wrapper">
  <a href="/%20/" class="logo">飞雪无情的博客</a>
</div>

<nav class="site-navbar">
  <ul id="menu" class="menu">
    <li class="menu-item">
      <a class="menu-item-link" href="/tools/">工具</a>
    </li><li class="menu-item">
      <a class="menu-item-link" href="/archives/">归档</a>
    </li><li class="menu-item">
      <a class="menu-item-link" href="/about/">关于</a>
    </li>
  </ul>
</nav><main class="main">
                <div class="container"><div class="toc" id="toc-auto">
            <h2 class="toc-title">Contents</h2>
            <div class="toc-content" id="toc-content-auto"></div>
        </div><article class="page single"><h1 class="single-title animated flipInX">《Flutter Engine源码调试》</h1><div class="post-meta">
            <div class="post-meta-line"><span class="post-author"><a href="/" title="Author" rel=" author" class="author"><i class="fas fa-user-circle fa-fw"></i>飞雪无情</a></span>&nbsp;<span class="post-category">included in <a href="/categories/Flutter/"><i class="far fa-folder fa-fw"></i>Flutter</a></span></div>
            <div class="post-meta-line"><i class="far fa-calendar-alt fa-fw"></i>&nbsp;<time datetime="2021-07-31">2021-07-31</time>&nbsp;<i class="fas fa-pencil-alt fa-fw"></i>&nbsp;2589 words&nbsp;
                <i class="far fa-clock fa-fw"></i>&nbsp;6 minutes&nbsp;</div>
        </div><div class="featured-image"><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/90c6cc12-742e-4c9f-b318-b912f163b8d0.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/90c6cc12-742e-4c9f-b318-b912f163b8d0.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/90c6cc12-742e-4c9f-b318-b912f163b8d0.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/90c6cc12-742e-4c9f-b318-b912f163b8d0.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/90c6cc12-742e-4c9f-b318-b912f163b8d0.png"
        title="https://luckly007.oss-cn-beijing.aliyuncs.com/img/90c6cc12-742e-4c9f-b318-b912f163b8d0.png" /></div><div class="details toc" id="toc-static"  kept="">
                <div class="details-summary toc-title">
                    <span>Contents</span>
                    <span><i class="details-icon fas fa-angle-right"></i></span>
                </div>
                <div class="details-content toc-content" id="toc-content-static"><nav id="TableOfContents">
  <ul>
    <li><a href="#flutter-engine源码编译">Flutter Engine源码编译</a>
      <ul>
        <li><a href="#源码下载">源码下载</a></li>
        <li><a href="#编译过程">编译过程</a></li>
      </ul>
    </li>
    <li><a href="#flutter-engine源码调试">Flutter Engine源码调试</a>
      <ul>
        <li><a href="#使用编译后flutter启动flutter应用">使用编译后Flutter启动Flutter应用</a></li>
        <li><a href="#向应用中添加lldb-server">向应用中添加lldb-server</a></li>
        <li><a href="#通过android-studio设置lldb">通过Android Studio设置lldb</a></li>
        <li><a href="#在ide中进行配置调试">在IDE中进行配置调试</a></li>
      </ul>
    </li>
  </ul>
</nav></div>
            </div><div class="content" id="content"><blockquote>
<p>本文主要介绍Flutter Engine</p>
</blockquote>
<p>之前进行了一些Flutter应用开发，了解了framework层面的渲染原理。发现Flutter不仅可以进行界面开发，还可以做很多其它的事情，但是这要求对于Flutter Engine的源码非常熟悉，最终对其进行修改。</p>
<p>Flutter Engine源码太多了，而且有很多第三方库，光下载源码以及依赖包就用了几个小时，总计有8G多。如果想要通过代码跟踪，很容易就缺失了相关内容，因此我选择对Flutter Engine源码进行调试，这种方式来熟悉代码。</p>
<h2 id="flutter-engine源码编译">Flutter Engine源码编译</h2>
<h3 id="源码下载">源码下载</h3>
<p>Flutter相关源码下载参考： <a href="https://github.com/flutter/flutter/wiki/Setting-up-the-Engine-development-environment">https://github.com/flutter/flutter/wiki/Setting-up-the-Engine-development-environment</a></p>
<p>注意：很多第三方代码托管在<code>chromium.googlesource.com</code>、<code>fuchsia.googlesource.com</code>、<code>skia.googlesource.com</code>等域名下，下载过程中需要开启git代理以及http、https代理服务。</p>
<h3 id="编译过程">编译过程</h3>
<p>下载过程时间很长，根据网络情况不同，大概需要几十分钟到几个小时不等。</p>
<h4 id="检出对应版本">检出对应版本</h4>
<p>首先获取当前Flutter版本的提交信息</p>
<pre><code>cat /Users/sunwenwu/flutter/bin/internal/engine.version # 当前使用的flutter目录
</code></pre><p>得到提交信息 <code>4737fc5cd89b8f0136e927b00f2e159444b95a73</code></p>
<p>然后将源码同步到指定的提交记录上：</p>
<pre><code>cd /Users/sunwenwu/flutter_engine/engine/src/flutter  # 下载后的Flutter Engine源码位置
git reset --hard 4737fc5cd89b8f0136e927b00f2e159444b95a73
gclient sync --with_branch_heads --with_tags
</code></pre><h4 id="编译android-arm-debug默认版本">编译Android arm Debug默认版本</h4>
<pre><code>cd /Users/sunwenwu/flutter_engine/engine/src
./flutter/tools/gn --android --android-cpu arm --unoptimized
ninja -C out/android_debug_unopt -j 8
./flutter/tools/gn --android-cpu arm --unoptimized
ninja -C out/host_debug_unopt -j 8
</code></pre><p>其中<code>--android-cpu</code>可以省略，默认就是arm格式，同时默认编译debug版本。</p>
<p>编译过程大概需要30分钟，每一步都需要十五分钟左右。编译完成后会生成<code>out/android_debug_unopt</code>与<code>out/host_debug_unopt</code>两个目录。到现在为止，编译过程已经完成。</p>
<h2 id="flutter-engine源码调试">Flutter Engine源码调试</h2>
<h3 id="使用编译后flutter启动flutter应用">使用编译后Flutter启动Flutter应用</h3>
<p>调试过程需要界面触发跟踪，因此我们还要准备一个Flutter工程。因为我们新编译的Flutter版本与原来的Flutter版本一致，所以可以直接使用原来已经创建好的Flutter项目。</p>
<p>我这里原来有一个比较简单的Flutter项目<code>flutter_app</code>，工程位置在<code>/Users/sunwenwu/project/flutter_app/flutter_app</code>。</p>
<p>在查看下编译好的Flutter目录（也就是android_debug_unopt目录下），可以看到有两个重要文件<code>flutter_java.jar</code>以及<code>libflutter.so</code>，这个就是Android项目中必须的两个依赖库。</p>
<p>下面我们设置flutter应用使用我们编译好的依赖库。</p>
<p>将手机通过USB线连接到PC上，开启调试模式（手机不需要ROOT）。</p>
<pre><code>cd /Users/sunwenwu/project/flutter_app/flutter_app
flutter run --local-engine-src-path=/Users/sunwenwu/flutter_engine/engine/src --local-engine=/Users/sunwenwu/flutter_engine/engine/src/out/android_debug_unopt
</code></pre><p>等待应用安装，安装完毕后，应用界面打开：</p>
<p><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        title="img" /></p>
<h3 id="向应用中添加lldb-server">向应用中添加lldb-server</h3>
<p>上面已经将libflutter.so加入到了应用中，如果想要调试Native代码，还需要通过lldb来实现。现在Android Studio中的调试Native代码也是这种方式来实现的。</p>
<p>lldb远程调试的配置方式参考：https://lldb.llvm.org/use/remote.html</p>
<p>按照上面文档配置后存在一个问题，就是最后挂载进程时，无法关联到我们的flutter应用进程。这个是因为系统权限限制，除非将手机ROOT，否则一直会提示<code>attach fail</code></p>
<p>那这个问题怎么解决？其实可以将lldb-server添加到需要调试的应用中。通过<code>run-as</code>获取应用权限，进入应用目录下进行操作。注意，使用<code>run-as</code>的应用只能是debug应用，其他应用不可以使用。</p>
<ul>
<li>首先确认安装lldb，在Android Studio的<code>SDK Manager</code>中可以进行安装或者看到安装状态：</li>
</ul>
<p><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        title="img" /></p>
<ul>
<li>找到lldb-server所在目录位置，并将其推送到手机中</li>
</ul>
<pre><code>cd /Users/sunwenwu/Library/Android/sdk/lldb/3.1/android/armeabi
adb push lldb-server /data/local/tmp/
</code></pre><ul>
<li>然后执行<code>run-as</code>命令将lldb-server写入到指定位置下</li>
</ul>
<pre><code>adb shell &quot;cat /data/local/tmp/lldb-server | run-as com.oldsun.flutter_app sh -c 'cat &gt; /data/data/com.oldsun.flutter_app/lldb-server'&quot;
</code></pre><p>这一步已经将lldb-server写入到了<code>/data/data/com.oldsun.flutter_app</code>文件夹中了</p>
<ul>
<li>进入应用中，启动lldb-server</li>
</ul>
<pre><code>adb shell
HWDLI-Q:/ $ run-as com.oldsun.flutter_app
HWDLI-Q:/data/data/com.oldsun.flutter_app $ chmod 700 /data/data/com.oldsun.flutter_app/lldb-server # 变更权限，可以执行相应操作
HWDLI-Q:/data/data/com.oldsun.flutter_app $ sh lldb-server platform --server --listen unix-abstract:///com.oldsun.flutter_app-0/debug.socket
</code></pre><ul>
<li>在另一个终端中执行<code>lldb</code>进行调试</li>
</ul>
<pre><code>lldb
(lldb) platform select remote-android
(lldb) platform connect unix-abstract-connect:///com.oldsun.flutter_app-0/debug.sock
(lldb) process attach -p 22572 # 关联对应进程
(lldb) add-dsym /Users/sunwenwu/flutter_engine/engine/src/out/android_debug_unopt/libflutter.so # 需要调试的动态库符号通知编译器
(lldb) settings set target.source-map /Users/sunwenwu/flutter_engine/engine/src/out/android_debug_unopt /Users/sunwenwu/flutter_engine/engine/src/  # 关联源码与编译符号
</code></pre><h3 id="通过android-studio设置lldb">通过Android Studio设置lldb</h3>
<p>上面的处理过程比较麻烦，实际上也有简单的办法执行。在Android Studio中启动应用，并<code>Attach Debugger to Android Process</code>，选择指定的应用。</p>
<p><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        title="img" /></p>
<p>这时就会自动将lldb_server注入到应用中的<code>/data/data/com.oldsun.flutter_app/lldb/bin/</code>目录下。</p>
<p>重新使用脚本启动flutter应用，再次执行<code>run-as com.oldsun.flutter_app</code>，可以看到</p>
<pre><code>adb shell
HWDLI-Q:/ $ run-as com.oldsun.flutter_app
HWDLI-Q:/data/data/com.oldsun.flutter_app $ ls
app_flutter cache files lib lldb
</code></pre><p>这时执行</p>
<pre><code>HWDLI-Q:/data/data/com.oldsun.flutter_app $ chmod 700 /data/data/com.oldsun.flutter_app/lldb/bin/lldb-server
HWDLI-Q:/data/data/com.oldsun.flutter_app $ chmod 700 /data/data/com.oldsun.flutter_app/lldb/bin/start_lldb_server.sh
HWDLI-Q:/data/data/com.oldsun.flutter_app $ sh /data/data/com.oldsun.flutter_app/lldb/bin/start_lldb_server.sh /data/data/com.oldsun.flutter_app/lldb unix-abstract /com.oldsun.flutter_app-0 debug.sock &quot;lldb process:gdb-remote packets&quot;
</code></pre><p>另起新的终端，执行</p>
<pre><code>lldb
(lldb) platform select remote-android
(lldb) platform connect unix-abstract-connect:///com.oldsun.flutter_app-0/debug.sock
(lldb) process attach -p 22572 # 关联对应进程
(lldb) add-dsym /Users/sunwenwu/flutter_engine/engine/src/out/android_debug_unopt/libflutter.so # 需要调试的动态库符号通知编译器
(lldb) settings set target.source-map /Users/sunwenwu/flutter_engine/engine/src/out/android_debug_unopt /Users/sunwenwu/flutter_engine/engine/src/  # 关联源码与编译符号
</code></pre><p>关联完毕。</p>
<p>到此调试配置已经结束。</p>
<h3 id="在ide中进行配置调试">在IDE中进行配置调试</h3>
<p>上面的配置项已经可以调试了，但是只能通过脚本执行，缺乏可视化交互界面，我们通常情况下都是通过IDE进行的调试。</p>
<p>IDE可以选择Android Studio或者Visual Studio Code，相比之下，前者需要设置为特定工程，配置较复杂，我们选择VS code来进行调试。</p>
<h4 id="安装相应扩展">安装相应扩展</h4>
<p>需要安装<code>C/C++</code>与<code>CodeLLDB</code>这两个插件，正常安装即可。</p>
<p><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/%E5%BA%94%E7%94%A8%E9%A6%96%E9%A1%B5.png"
        title="img" /></p>
<h4 id="导入源码">导入源码</h4>
<p>在VS Code中打开文件夹，选择Flutter Engine源码所在的目录，导入。</p>
<h4 id="configuration">Configuration</h4>
<p>VS Code中选择<code>Debug-&gt;Open Configuration</code>，在打开的<code>launch.json</code>文件中配置如下内容：</p>
<pre><code>{
    &quot;version&quot;: &quot;0.2.0&quot;,
    &quot;configurations&quot;: [
    {
      &quot;type&quot;: &quot;lldb&quot;,
      &quot;request&quot;: &quot;attach&quot;,
      &quot;name&quot;: &quot;android_attach&quot;,
      &quot;pid&quot;: &quot;22572&quot;, // use ${command:pickProcess} to pick other users' processes
      &quot;initCommands&quot;: [
        &quot;platform select remote-android&quot;,
        &quot;platform connect unix-abstract-connect:///com.oldsun.flutter_app-0/debug.sock&quot;
      ],
      &quot;postRunCommands&quot;: [
        &quot;add-dsym /Users/sunwenwu/flutter_engine/engine/src/out/android_debug_unopt/libflutter.so&quot;,
        &quot;settings set target.source-map /Users/sunwenwu/flutter_engine/engine/src/out/android_debug_unopt /Users/sunwenwu/flutter_engine/engine/src/&quot;
      ],
    }
    ]
  }
</code></pre><p>这里面的配置项就是上面脚本中的lldb设置，保存文件。</p>
<h4 id="开始调试">开始调试</h4>
<p>在<code>src/flutter/lib/ui/window/window.cc</code>文件中的<code>Render</code>方法31行设置断点。</p>
<p><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213555774.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213555774.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213555774.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213555774.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213555774.png"
        title="image-20210731213555774" /></p>
<p>断点设置完成后，按<code>F5</code>键，开始进行调试，如下图。</p>
<p><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213609832.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213609832.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213609832.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213609832.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213609832.png"
        title="image-20210731213609832" /></p>
<p>手机上触发刷新界面操作，断点卡顿，等待执行</p>
<p><img
        class="lazyload"
        src="/svg/loading.min.svg"
        data-src="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213622142.png"
        data-srcset="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213622142.png, https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213622142.png 1.5x, https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213622142.png 2x"
        data-sizes="auto"
        alt="https://luckly007.oss-cn-beijing.aliyuncs.com/img/image-20210731213622142.png"
        title="image-20210731213622142" /></p>
<blockquote>
<p>注意，上面的方式需要先设置断点再进行调试。</p>
</blockquote></div><div class="post-footer" id="post-footer">
    <div class="post-info">
        <div class="post-info-line">
            <div class="post-info-mod">
                <span>Updated on 2021-07-31</span>
            </div>
            <div class="post-info-license"></div>
        </div>
        <div class="post-info-line">
            <div class="post-info-md"></div>
            <div class="post-info-share">
                <span></span>
            </div>
        </div>
    </div>

    <div class="post-info-more">
        <section class="post-tags"><i class="fas fa-tags fa-fw"></i>&nbsp;<a href="/tags/flutter/">flutter</a></section>
        <section>
            <span><a href="javascript:void(0);" onclick="window.history.back();">Back</a></span>&nbsp;|&nbsp;<span><a href="/">Home</a></span>
        </section>
    </div>

    <div class="post-nav"><a href="/posts/flutter/FutureBuilder%E4%B8%8EStreamBuilder/" class="prev" rel="prev" title="《FutureBuilder与StreamBuilder》"><i class="fas fa-angle-left fa-fw"></i>《FutureBuilder与StreamBuilder》</a>
            <a href="/posts/flutter/Flutter%E6%B5%8B%E8%AF%95%E8%84%9A%E6%9C%AC%E5%BC%80%E5%8F%91/" class="next" rel="next" title="《Flutter测试脚本开发》">《Flutter测试脚本开发》<i class="fas fa-angle-right fa-fw"></i></a></div>
</div>
</article></div>
            </main><footer class="footer">
        <div class="footer-container"><div class="footer-line">Powered by <a href="https://gohugo.io/" target="_blank" rel="noopener noreffer" title="Hugo 0.79.1">Hugo</a> | Theme - <a href="https://github.com/dillonzq/LoveIt" target="_blank" rel="noopener noreffer" title="LoveIt 0.2.10"><i class="far fa-kiss-wink-heart fa-fw"></i> LoveIt</a>
                </div><div class="footer-line"><i class="far fa-copyright fa-fw"></i><span itemprop="copyrightYear">2021</span><span class="author" itemprop="copyrightHolder">&nbsp;<a href="/" target="_blank">飞雪无情</a></span></div>
        </div>
    </footer></div>

        <div id="fixed-buttons"><a href="#" id="back-to-top" class="fixed-button" title="Back to Top">
                <i class="fas fa-arrow-up fa-fw"></i>
            </a><a href="#" id="view-comments" class="fixed-button" title="View Comments">
                <i class="fas fa-comment fa-fw"></i>
            </a>
        </div><script type="text/javascript" src="/lib/smooth-scroll/smooth-scroll.min.js"></script><script type="text/javascript" src="/lib/lazysizes/lazysizes.min.js"></script><script type="text/javascript" src="/lib/clipboard/clipboard.min.js"></script><script type="text/javascript" src="/lib/sharer/sharer.min.js"></script><script type="text/javascript">window.config={"code":{"copyTitle":"Copy to clipboard","maxShownLines":10},"comment":{}};</script><script type="text/javascript" src="/js/theme.min.js"></script></body>
</html>
